| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a steel pipe with a projection, which has low possibility of burn-through and thermal deformation of the steel pipe and can secure a sufficient penetration amount to the steel pipe.SOLUTION: A pair of patches 2, 2 are arranged on an inner surface of a steel pipe 1 at intervals. In carrying out build-up welding between the patches while relatively moving the patches 2, 2 and a welding torch 5 to the inner surface of the steel pipe 1, an axial direction of the welding torch 5 is inclined with respect to a vertical direction so that an upper side of the welding torch 5 inclines to an opposite side to a moving direction of the steel pipe 1. Thus, in carrying out the build-up welding on the inner surface of the steel pipe, it is less likely that burn-through and thermal deformation of the steel pipe occur, and a sufficient penetration amount to the steel pipe can be secured. |
